let person1 ={
    say: function(){
        console.log('hi')
    },
    sing: function(){
        console.log('balabala')
    }
}
// 以上内容可以简写为：
let person2 ={
    say(){
        console.log('hi')
    },
    sing(){
        console.log('balabala')
    }
}
person2.say()
person2.sing()